Metamath Proof Explorer


Theorem rhmmhm

Description: A ring homomorphism is a homomorphism of multiplicative monoids. (Contributed by Stefan O'Rear, 7-Mar-2015)

Ref Expression
Hypotheses isrhm.m M = mulGrp R
isrhm.n N = mulGrp S
Assertion rhmmhm F R RingHom S F M MndHom N

Proof

Step Hyp Ref Expression
1 isrhm.m M = mulGrp R
2 isrhm.n N = mulGrp S
3 1 2 isrhm F R RingHom S R Ring S Ring F R GrpHom S F M MndHom N
4 3 simprbi F R RingHom S F R GrpHom S F M MndHom N
5 4 simprd F R RingHom S F M MndHom N